Disable label submit button if any field is empty

app/assets/javascripts/application.js.coffee

@@ -53,15 +53,40 @@ window.split = (val) ->
 window.extractLast = (term) ->
   return split( term ).pop()
 
+window.rstrip = (val) ->
+  return val.replace(/\s+$/, '')
+
 # Disable button if text field is empty
 window.disableButtonIfEmptyField = (field_selector, button_selector) ->
   field = $(field_selector)
   closest_submit = field.closest("form").find(button_selector)
 
-  closest_submit.disable() if field.val().replace(/\s+$/, "") is ""
+  closest_submit.disable() if rstrip(field.val()) is ""
 
   field.on "input", ->
-    if $(@).val().replace(/\s+$/, "") is ""
+    if rstrip($(@).val()) is ""
+      closest_submit.disable()
+    else
+      closest_submit.enable()
+
+# Disable button if any input field with given selector is empty
+window.disableButtonIfEmptyField = (form, form_selector, button_selector) ->
+  closest_submit = form.find(button_selector)
+  empty = false
+  form.find('input').filter(form_selector).each ->
+    empty = true if rstrip($(this).val()) is ""
+
+  if empty
+    closest_submit.disable()
+  else
+    closest_submit.enable()
+
+  form.keyup ->
+    empty = false
+    form.find('input').filter(form_selector).each ->
+      empty = true if rstrip($(this).val()) is ""
+
+    if empty
       closest_submit.disable()
     else
       closest_submit.enable()

app/assets/javascripts/dispatcher.js.coffee

@@ -42,6 +42,8 @@ class Dispatcher
         new TreeView()
       when 'projects:blob:show'
         new BlobView()
+      when 'projects:labels:new'
+        new Labels()
 
     switch path.first()
       when 'admin' then new Admin()

app/assets/javascripts/labels.js.coffee

+class Labels
+  constructor: ->
+    # find the form
+    form = $('.label-form')
+    @setupLabelForm(form)
+
+  ###
+  General note form setup.
+
+  deactivates the submit button when text is empty
+  hides the preview button when text is empty
+  setup GFM auto complete
+  show the form
+  ###
+  setupLabelForm: (form) ->
+    disableButtonIfEmptyField form, '.form-control', form.find('.js-save-button')
+
+@Labels = Labels

app/views/projects/labels/_form.html.haml

@@ -28,7 +28,7 @@
              
 
   .form-actions
-    = f.submit 'Save', class: 'btn btn-save'
+    = f.submit 'Save', class: 'btn btn-save js-save-button'
     = link_to "Cancel", project_labels_path(@project), class: 'btn btn-cancel'